Washington, Jan 24 (IANS) For millions of diabetics around the world, drawing blood is the most prevalent method of checking glucose levels, an invasive and rather painful method. Now Brown University researchers are working on a new sensor that can check blood sugar levels by measuring glucose concentrations in saliva instead.

The technique takes advantage of a convergence of nanotechnology and surface plasmonics, which explores the interaction of electrons and photons (light atoms), the journal Nano Letters reports.

Brown engineers etched thousands of plasmonic interferometers onto a fingernail-size biochip and measured the concentration of glucose molecules in water on the chip, according to a Brown statement.

Interferometers are instruments that measure biomolecular interactions, wavelengths, very small distances and thicknesses in various scientific disciplines.

“This is proof of concept that plasmonic interferometers can be used to detect molecules in low concentrations, using a footprint that is 10 times smaller than a human hair,” said Domenico Pacifici, assistant professor of engineering at Brown, who led the study.

Their results showed that the specially designed biochip could detect glucose levels similar to the levels found in human saliva. Glucose in human saliva is typically about 100 times less concentrated than in the blood.

The technique can be used to detect other chemicals or substances, from anthrax to biological compounds, Pacifici said.